Signaling for downlink coordinated multipoint in a wireless communication system

Abstract

Embodiments herein describe apparatuses, systems, and methods for signaling to support downlink coordinated multipoint (CoMP) communications with a user equipment (UE) in a wireless communication network. In embodiments, the UE may be configured with a plurality of channel state information (CSI) processes (e.g., via radio resource control (RRC) signaling) to use for providing CSI feedback to an evolved Node B (eNB) to support downlink CoMP communications. The UE may be configured with a plurality of sets of CSI processes. The UE may further receive a downlink control information (DCI) message from the eNB that indicates one of the configured sets of CSI processes on which the UE is to provide CSI feedback to the UE. The UE may generate the CSI feedback for the indicated set of CSI processes, and transmit the CSI feedback to the eNB in a CSI report.

What is claimed is:  
     
       1. One or more non-transitory machine-readable storage media, having instructions stored thereon that, when executed by one or more processors, cause a user equipment (UE) to:
 receive physical downlink shared channel (PDSCH) resource element (RE) parameters for a plurality of PDSCH mapping parameter sets, wherein individual PDSCH RE mapping parameter sets of the plurality of PDSCH mapping parameter sets include a number of antenna ports, a cell-specific reference signal (CRS) frequency shift, and a non-zero power channel state information reference signal (CSI-RS) identifier; 
 detect a value in a PDSCH RE mapping field of a downlink control information (DCI) message received from an evolved Node B (eNB), wherein the value is represented in the PDSCH RE mapping field by two bits; 
 identify, based on the value, a PDSCH RE mapping parameter set from the plurality of PDSCH RE mapping parameter sets; and 
 process the PDSCH RE mapping parameter set to receive a PDSCH. 
 
     
     
       2. The one or more non-transitory machine-readable storage media of  claim 1 , wherein the number of antenna ports includes 1, 2 or 4. 
     
     
       3. The one or more non-transitory machine-readable storage media of  claim 1 , wherein the PDSCH RE mapping field is to support a coordinated multipoint (CoMP) communication to the UE. 
     
     
       4. The one or more non-transitory machine-readable storage media of  claim 1 , wherein the individual PDSCH RE mapping parameter sets further include a PDSCH starting symbol, or a multicast-broadcast single frequency network subframe configuration. 
     
     
       5. The one or more non-transitory machine-readable storage media of  claim 1 , wherein the message is further to indicate a serving cell that the UE uses to receive the PDSCH. 
     
     
       6. The one or more non-transitory machine-readable storage media of  claim 1 , wherein the plurality of PDSCH RE mapping parameter sets have four PDSCH RE mapping parameter sets. 
     
     
       7. An apparatus to be employed by a user equipment (UE), comprising:
 communication circuitry to:
 receive physical downlink shared channel (PDSCH) resource element (RE) parameters for four PDSCH mapping parameter sets, wherein individual PDSCH RE mapping parameter sets of the four PDSCH mapping parameter sets include a number of antenna ports, a cell-specific reference signal (CRS) frequency shift, and a non-zero power channel state information reference signal (CSI-RS) identifier; 
 receive, from an evolved Node B (eNB), a downlink control information (DCI) message having a value in a PDSCH RE mapping field, wherein the value is represented in the PDSCH RE mapping field by two bits; and 
 
 management circuitry coupled to the communication circuitry, the management circuitry to:
 identify, based on the value, a PDSCH RE mapping parameter set from the four PDSCH RE mapping parameter sets; and 
 process the PDSCH RE mapping parameter set to receive a PDSCH. 
 
 
     
     
       8. The apparatus of  claim 7 , wherein the number of antenna ports includes 1, 2 or 4. 
     
     
       9. The apparatus of  claim 7 , wherein the PDSCH RE mapping field is to support a coordinated multipoint (CoMP) communication to the UE. 
     
     
       10. The apparatus of  claim 7 , wherein the PDSCH RE mapping parameter set is further to include a PDSCH starting symbol, or a multicast-broadcast single frequency network subframe configuration. 
     
     
       11. The apparatus of  claim 7 , wherein the message is further to indicate a serving cell that the UE uses to receive the PDSCH. 
     
     
       12. An apparatus to be employed by an evolved Node B (eNB), the apparatus comprising:
 management circuitry to:
 determine four physical downlink shared channel (PDSCH) resource element (RE) mapping parameter sets, each PDSCH RE mapping parameter set having a number of antenna ports, a cell-specific reference signal (CRS) frequency shift, and a non-zero power channel state information reference signal (CSI-RS) identifier; and 
 determine a value in a PDSCH RE mapping field, the value corresponding to a PDSCH RE mapping parameter set of the four PDSCH RE mapping parameter sets, wherein the value is represented in the PDSCH RE mapping field by two bits; and 
 
 communication circuitry coupled to the management circuitry, the communication circuitry to:
 transmit configuration information to a user equipment (UE) to configure the four PDSCH RE mapping parameter sets for the UE; and 
 transmit a downlink control information (DCI) message including the value in the PDSCH RE mapping field to the UE over a wireless communication network to identify the PDSCH RE mapping parameter set of the four PDSCH RE mapping parameter sets that is to be used by the UE. 
 
 
     
     
       13. The apparatus of  claim 12 , wherein the number of antenna ports includes 1, 2 or 4. 
     
     
       14. The apparatus of  claim 12 , wherein the PDSCH RE mapping field is to support a coordinated multipoint (CoMP) communication to the UE. 
     
     
       15. The apparatus of  claim 12 , wherein the PDSCH RE mapping parameter set is further to have a PDSCH starting symbol, or a multicast-broadcast single frequency network subframe configuration. 
     
     
       16. The apparatus of  claim 12 , wherein the message is further to indicate a serving cell that the UE uses to receive the PDSCH. 
     
     
       17. An apparatus to be employed by a user equipment (UE), the apparatus comprising:
 communication circuitry to receive, from an evolved Node B (eNB), a message having a downlink control information (DCI) format to support coordinated multipoint (CoMP) communications, the message including a value in a channel state information (CSI) request field and a CodebookSubsetRestriction parameter associated with individual CSI processes to indicate a subset of precoding matrix indicators within a codebook to be used by the UE for CSI reporting; and 
 feedback circuitry coupled to the communication circuitry, the feedback circuitry to generate an aperiodic CSI feedback for a pre-configured set of one or more CSI processes based on the CodebookSubsetRestriction parameter, the pre-configured set identified by the value in the CSI request field, 
 wherein the individual CSI processes are associated with a CSI reference signal (CSI-RS) resource and a CSI-interference measurement (CSI-IM) resource, and 
 wherein the one or more CSI processes in the pre-configured set are associated with one serving cell, and are a subset of a total number of CSI processes of the serving cell. 
 
     
     
       18. The apparatus of  claim 17 , wherein the value is a two-bit value that identifies the one or more CSI processes, wherein the one or more CSI processes are associated with the serving cell on which the message is received. 
     
     
       19. The apparatus of  claim 17 , wherein the value is a two-bit value that identifies the one or more CSI processes, wherein the one or more CSI processes are associated with the serving cell that is different from another serving cell on which the message is received. 
     
     
       20. The apparatus of  claim 17 , wherein the communication module is further to receive another message in the DCI format, the other message to have a CSI request field with a two-bit value that represents no aperiodic CSI report is triggered. 
     
     
       21. The apparatus of  claim 17 , wherein the feedback circuitry is further to configure the one or more CSI processes based on a bitmap received from the eNB, wherein:
 the bitmap comprises multiple groups of bits; 
 individual groups of the multiple groups correspond to individual configured serving cells including the serving cell; and 
 individual bits of a group correspond to individual CSI processes of a configured serving cell that corresponds to the group. 
 
     
     
       22. The apparatus of  claim 17 , wherein the aperiodic CSI feedback includes a channel quality indicator (CQI), a precoding matrix indicator (PMI), a precoding type indicator, or a rank indicator (RI). 
     
     
       23. The apparatus of  claim 17 , wherein the user equipment is a mobile device having a touchscreen user interface. 
     
     
       24. A method employed by an evolved Node B (eNB), comprising:
 generating a message having a downlink control information (DCI) format supporting coordinated multipoint (CoMP) communications, the message including a value in a channel state information (CSI) request field and a CodebookSubsetRestriction parameter associated with individual CSI processes to indicate a subset of precoding matrix indicators within a codebook to be used for CSI reporting; 
 transmitting the message to a user equipment (UE) over a wireless communication network; and 
 receiving an aperiodic CSI feedback for a pre-configured set of one or more CSI processes, the pre-configured set identified by the value in the CSI request field; 
 wherein the individual CSI processes are associated with a CSI reference signal (CSI-RS) resource and a CSI-interference measurement (CSI-IM) resource; and 
 wherein the one or more CSI processes of the pre-configured set are associated with one serving cell, and are a subset of a total number of CSI processes of the serving cell. 
 
     
     
       25. The method of  claim 24 , wherein the value is a two-bit value that identifies the one or more CSI processes, wherein the one or more CSI processes are associated with the serving cell on which the message is received. 
     
     
       26. The method of  claim 24 , wherein the value is a two-bit value that identifies the one or more CSI processes, wherein the one or more CSI processes are associated with the serving cell that is different than another serving cell on which the message is received. 
     
     
       27. The method of  claim 24 , further comprising:
 transmitting another message in the DCI format to the UE, wherein the other message has a CSI request field with a two-bit value that represents no aperiodic CSI report is triggered. 
 
     
     
       28. The method of  claim 24 , further comprising:
 generating a bitmap comprising multiple groups of bits, wherein individual groups of the multiple groups correspond to individual configured serving cells including the serving cell, and individual bits of a group corresponding to individual CSI processes of a configured serving cell that corresponds to the group; and 
 transmitting the bitmap to the UE. 
 
     
     
       29. The method of  claim 24 , wherein the aperiodic CSI feedback includes a channel quality indicator (CQI), a precoding matrix indicator (PMI), a precoding type indicator, or a rank indicator (RI).